U.S. patent number 5,032,850 [Application Number 07/452,686] was granted by the patent office on 1991-07-16 for method and apparatus for vapor jet printing.
This patent grant is currently assigned to Tokyo Electric Co., Ltd.. Invention is credited to Gerry B. Andeen, Ayumu Makino, Yasuo Matsumoto, Hisashi Nishikawa, Ronald Swidler.
United States Patent |
5,032,850 |
Andeen , et al. |
July 16, 1991 |
Method and apparatus for vapor jet printing
Abstract
A method of vapor jet printing is described, along with several
embodiments of apparatus for practicing such method. The vapor
phase of a sublimable dye is mixed with a carrier gas. The
resulting mixture is then jetted toward a recording medium. The
carrier gas in indirectly heated by the sublimable dye to maintain
the latter in its vaporous state during its travel to the recording
medium. One embodiment of the apparatus includes a removable
cartridge for the sublimable dye which enables color
interchangeability and a limited downtime for dye recharging.
Inventors: |
Andeen; Gerry B. (Pandan
Valley, SG), Swidler; Ronald (Palo Alto, CA),
Nishikawa; Hisashi (Shizuoka, JP), Matsumoto;
Yasuo (Shizuoka, JP), Makino; Ayumu (Shizuoka,
JP) |
Assignee: |
Tokyo Electric Co., Ltd.
(Tokyo, JP)
|
Family
ID: |
23797490 |
Appl.
No.: |
07/452,686 |
Filed: |
December 18, 1989 |
Current U.S.
Class: |
347/15; 347/21;
347/83; 347/43 |
Current CPC
Class: |
B41J
2/215 (20130101); B41J 2/2103 (20130101) |
Current International
Class: |
B41J
2/21 (20060101); B41J 2/215 (20060101); B41J
002/015 (); B41J 002/21 () |
Field of
Search: |
;346/1.1,140 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
|
|
|
|
0124116 |
|
Nov 1984 |
|
EP |
|
50-11291 |
|
Sep 1975 |
|
JP |
|
52-13861 |
|
Nov 1977 |
|
JP |
|
52-138615 |
|
Nov 1977 |
|
JP |
|
55-76149 |
|
Jun 1980 |
|
JP |
|
57-132476 |
|
Jul 1982 |
|
JP |
|
58-8189 |
|
Jan 1983 |
|
JP |
|
1482596 |
|
Jul 1974 |
|
GB |
|
2122951 |
|
Apr 1983 |
|
GB |
|
Other References
M L. Levine et al., "Material Transfer Recording", Applied Optics,
vol. 9, No. 10, Oct. 1970, pp. 2260-2265. .
C. A. Bruce and J. T. Jacobs, "Laser Transfer of Volatile Dyes", J.
Appl. Photographic Engineering, vol. 3, No. 1, Winter 1977, pp.
40-43. .
R. S. Braudy, "Laser Writing", Proc. IEEE, Oct. 1969, pp.
1771-1772. .
Robert S. Braudy, "Characteristics of Organic Colorants Transferred
by Laser Scanning", J. Appl. Physics, vol. 45, No. 8, Aug. 1974,
pp. 3512-3515..
|
Primary Examiner: Hartary; Joseph W.
Attorney, Agent or Firm: Flehr, Hohbach, Test, Albritton
& Herbert
Claims
We claim:
1. In a method of applying a coloring agent to a recording medium,
the steps of:
mixing the coloring agent with a carrier gas in a chamber having a
gated nozzle while the coloring agent is in a vaporous state and
said carrier gas is under a pressure in the range of 0.1 to 2.0
psi, thereby to form a mixture thereof in said chamber;
positioning the gated nozzle of said chamber facing said recording
medium;
thereafter ejecting said mixture toward a desired location on the
recording medium at said pressure in the range of 0.1 to 2.0 psi by
opening and closing the gate of said nozzle to divide the mixture
into predetermined amounts;
varying the number of said predetermined amounts ejected toward
said desired location at any given time proportionate to the amount
of said mixture desired at said location at such time; and
oscillating said gate between an open and closed state by applying
a high frequency control signal of sufficiently high frequency that
said mixture is maintained at an ejecting pressure within said
range.
2. A method as recited in claim 1, wherein said coloring agent is a
sublimable dye and said chamber has a temperature of from about
400.degree. F. to about 500.degree. F.
3. A method as recited in claim 1, wherein said step of oscillating
said gate further includes the step of oscillating said control
signal at a frequency of approximately 2,000 Hz.
4. In an apparatus for applying a color agent to a recording
medium, the combination of:
a source of a coloring agent in a vaporous state;
a source of a carrier as under pressure in the range of 0.1 to 2.0
psi;
a chamber;
means connecting said sources together to mix in said chamber the
carrier gas with the coloring agent while the latter is in a
vaporous sate and thereby form a pressurized mixture thereof;
a nozzle for ejecting the pressurized mixture of said carrier gas
and coloring agent toward a desired location on the recording
medium at said pressure in the range of 0.1 to 2.0 psi;
a gate at said nozzle for opening and closing said nozzle to
control flow of said pressurized mixture from said nozzle, the
opening and closing of said gate thereby dividing the mixture into
predetermined amounts; and
an image signal source for controlling the opening and closing of
said gate; said image signal source providing a high frequency
pulsating signal for oscillating said gate between an open and
closed state at a sufficiently high frequency to maintain said
mixture at a stable ejection pressure in said range; and said
pulses having the same frequency and amplitude in a predetermined
time interval, whereby a selected amount of said mixture of said
carrier gas and coloring agent is ejected form said nozzle toward
said recording medium.
5. An apparatus as recited in claim 4, wherein said source of
coloring agent in a vaporous state includes a container for a
sublimable dye in solid form, heating means for transforming a
portion of said sublimable dye to its vaporous state, a power
source for said heating means, and an adjusting means for varying
the thermal energy output of said heating means.
6. An apparatus as recited in claim 4, wherein said source of said
coloring agent is one of a plurality of stand-alone cartridges for
containing a selected coloring agent when said cartridge is
separated from the remainder of said apparatus, which cartridge is
securable to said apparatus to cooperate with said source of
carrier gas, said connecting means and said nozzle by supplying
coloring agent to be applied to a recording medium.
7. An apparatus as recited in claim 4, wherein said high frequency
pulsating signal has a frequency of approximately 2,000 Hz.
8. In an apparatus for applying a coloring agent to a recording
medium, the combination of:
a source of a carrier gas under pressure in the range of 0.1 to 2.0
psi;
a nozzle having an inlet for receiving a coloring agent and an
outlet for ejecting a coloring agent toward a recording medium;
a plurality of individually securable stand-along cartridge means
for holding selected coloring agents separate from the remainder of
said apparatus, such tat the coloring agent in one of said
cartridge means is different from the coloring agent in at least
one other of said cartridge means and each individually securable
cartridge means further comprising:
a containment portion for holding a sublimable coloring agent in a
vaporous state in a first region thereof and in a solid state in an
adjacent region thereof;
tubular means for conveying said gas while it is under said
pressure in the range of 0.1 to 2.0 psi to said first region of
said containment portion whereby said vaporous coloring agent and
carrier gas are mixed to form a pressurized mixture, and said
tubular means has an inlet for sealable engaging said source of gas
under pressure and an outlet disposed in said first region of said
containment portion; and
passage means having a first end disposed in said first region of
said containment portion apart from said tubular means and having
an ejection bend for matingly engaging said inlet of said nozzle
whereby said pressurized mixture of gas and coloring agent is
ejected into said nozzle and to said recording medium.
9. An apparatus as recited in claim 8, wherein said apparatus for
applying a coloring agent further has a heater means provided in a
surface thereof disposed for adjacent contact with said containment
portion of said individually securable cartridge means to heat said
dye to a temperature of from about 400.degree. F. to about
500.degree. F. to cause said sublimable coloring agent to pass to a
vaporous state.
Description
BACKGROUND OF THE INVENTION
The present invention relates to the production of images or
representations, such as in high-speed printing. More particularly,
it relates to a method and apparatus for effectively applying a
coloring agent to a recording medium.
Most printing of alphanumeric characters is accomplished by impact
printing. That is, in general, a mechanical member of one sort or
another which defines all or part of each of the characters to be
imprinted, is used to impact an ink or coloring agent medium.
However, because of a desire of high-speed printing , less noise,
etc., much effort has been expended toward non-impact printing.
Some of this effort has been devoted to attempting to provide a
commercially successful vapor jet printing mechanism. Such a
mechanic is one in which a vaporous coloring agent is transferred
via a jetting action to a recording medium.
The approach used most often in vapor jet printing, has been to
attempt to print dots which can be arranged to define desired
alphanumeric characters. For such a method to provide quality
printing with the high resolution necessary, the dots which are
provided on the recording medium must be quite small. Moreover, the
location of such dots on the recording medium must be accurately
controllable.
It will be appreciated that the manner of transferring the coloring
agent to the recording medium is an important part of vapor jet
printing, particularly in connection with assuring small dot size
and accurate control over printing location. Many vapor jet
printing arrangements considered in the past have utilized
electrical deflection means to provide the transfer. In these
schemes the coloring agent is charged and then deflected to a
desired location. Such schemes have various disadvantages, a
primary one being decomposition of the coloring agent if it is, as
in most situations, the vapor state of a sublimable dye. Moreover,
most of such arrangements require relatively large spacing between
the jet from which the coloring agent emanates and the recording
medium, to accommodate the deflection and charging mechanism. The
coloring agent, if it is heated such as is typical for a sublimable
dye, can be cooled by the atmosphere in such space and solidified
before it reaches the recording medium. This, of course, results in
a degraded image. Also, most applications for vapor jet printing
require multiple jets of one or more coloring agents. The necessity
with this approach of controlling the individual jets of coloring
agent results in added complexity. Examples of this approach are
disclosed in Japanese Patent Publication Nos. 56-2020; 54-71636;
and 54-71637.
Other arrangements which have been considered rely simply on the
vapor pressure of the coloring agent itself to provide a jetting
action, i.e., there is no means for forcibly jetting the vaporous
coloring agent. Such a method is described, for example, in
Japanese Patent Publication No. 57-1771. One problem with this
approach is that in periodic passes of a coloring agent through a
jetting nozzle, the coloring agent of one pass may be left in the
nozzle because of the low pressure or force used to eject the same.
This earlier coloring agent is mixed with the subsequent coloring
agent passed through the nozzle and thus changes the amount which
is jetted. This deleteriously affects the parameters of printing.
Moreover, when the coloring agent is a condensable vapor, it may
condense in the nozzle and restrict the same. While heating of
vapors has been employed to raise the vapor pressure of the
coloring agent, such heating has not solved the nozzle
problems.
It also has been proposed to use a gas such as air as a carrier to
transport vaporous dyes to the recording medium. Japanese Patent
Publication No. 59-22759 is an example of such an arrangement. U.S.
Pat. No. 3,950,967 discloses such an arrangement designed for
coloring a textile material. Mechanisms which have relied upon this
procedure have been less than ideal. One major problem is that it
is difficult to control the amount of coloring agent which is
transferred during any selected period, i.e., the amount of
coloring agent within the gas carrier stream varies. This lack of
control, interferes of course, with color proportioning, obtaining
desired color densities, etc. Moreover, the use of the gaseous
stream of this nature can result in solidification of vaporous
coloring agents, such as sublimable dyes in their vapor state. It
also should be mentioned that the system of Japanese Patent
Publication No. 59-22759 utilizes a relatively expensive laser
optical system to form a vaporous coloring agent from solid,
sublimable dye rods. It is difficult to incorporate such a system
into a multi-head arrangement because of the relatively complex
optical and delivery systems utilized in such arrangement, and also
to control the gating "on and off" of the formation of the desired
vaporous dyes.
SUMMARY OF THE INVENTION
The present invention is a method and apparatus for applying a
coloring agent to a recording medium which does not have the
disadvantages of prior art approaches discussed above. While a
carrier gas, such as air, is used to transport the coloring agent
to the recording medium, in accordance with the invention it is
mixed with the coloring agent while the latter is in its vaporous
state before being ejected toward the recording medium. Most
desirably, the coloring agent and gas are intimately mixed together
to form a generally uniform mixture prior to being ejected. It will
be recognized that this will assure that a selected known amount of
coloring agent will be ejected toward the recording medium. Also
most desirably, the mixture is pressurized to be ejected in a
controlled manner at a pressure of from about 0.1 to about 2.0
p.s.i. toward the recording medium. This pressurization simply is
achieved by providing the carrier gas itself under a desired
pressure when it is maixed with the coloring agent, and it has been
found that recording at speeds of from 5 to 20 cm/sec can
advantageously can be used.
The carrier gas is heated to maintain the coloring agent in a
vaporous phase during use of such gas to transport the coloring
agent to the recording medium. This is most easily accomplished by
passing the gas mixture through a channel the temperature of which
is maintained at an appropriate level. Most simply and desirably,
the coloring agent is a sublimable dye in solid form which is
heated to form a vaporous dye which is then mixed with the carrier
gas to form the desired, heated mixture. To achieve this end it is
preferred to use chamber temperatures of from about 400 degrees F
to about 500 degrees F and nozzle diameters of from about 20
micrometers to about 125 micrometer.
As another salient feature of the instant invention, the coloring
agent is provided in a stand-alone cartridge which can be
interchangeably connected with the remainder of the apparatus,
including the ejection nozzle, to complete the arrangement. It will
be recognized that the provision of such a cartridge simplifies the
operation of providing new coloring agent or changing colors, and
significantly reduces the down-time associated therewith.
As will be appreciated from the more detailed description of a
preferred embodiment, the simplicity of the method and apparatus of
the invention lends itself well to multi-head arrangements, i.e.,
arrangements having a plurality of sources of coloring agents and a
plurality of nozzles. Moreover, it is particularly applicable to
use of sublimable dyes as the coloring agents.
BRIEF DESCRIPTION OF THE DRAWINGS
With reference to the accompanying three sheets of drawing:
FIG. 1. is a perspective view of a schematic representation of a
first embodiment of the instant invention;
FIG. 2 is a sectional view of the embodiment of FIG. 1;
FIG. 3 is a second sectional view of such embodiment taken on a
plane indicated by the lines 3--3 in FIG. 2 and including a
representation of a recording medium and an image signal
source;
FIG. 4 is another sectional view of the embodiment of FIG. 1, taken
on a plane indicated by the lines 4--4 in FIG. 2;
FIGS. 5 and 6 are enlarged sectional and broken-away views of
gating mechanisms for the nozzles of the embodiment of FIG. 1;
FIGS. 7 and 8 are schematic graphic representations of image
signals;
FIG. 9 is a view similar to he view of FIG. 2, showing an alternate
embodiment;
FIG. 10 is a sectional view similar to FIG. 3 of a third embodiment
of the instant invention; and
FIG. 11 is a sectional view of a schematic representation of a
fourth embodiment of the invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
The first preferred embodiment of the apparatus of the invention is
illustrated in FIGS. 1-5. A recording head for applying four
differing coloring agents to a recording medium is generally
referred to by the reference numeral 11. As is best illustrated in
FIGS. 1 and 2, such recording head 11 includes four chambers 12-15
individually containing sublimable dyes in solid form to produce
desired vaporous coloring agents. While in the drawing the
sublimable dyes in solid form are schematically illustrated in the
chambers 12-15 as blocks 16-19, respectively, it is preferred that
they be provided as is typical in powder form. The dyes could be of
any desired color which is available. The sublimable dye 16 could
be, for example, a cyan dye, the sublimable dye 17 could be a
magenta dye, the sublimable dye 18 could be a yellow dye, and the
dye 19 could be a black dye. A blocked entrance for supplying dye
in powder form is provided for each of the chambers, and is
schematically represented at 21 in FIG. 3 for chamber 13.
A source of heat in the form of a heater 22 is included within the
base wall of the recording head 11 to provide simultaneous heating
of the sublimable dyes in the four chambers 12-15. Such heater is
preferably an electrical resistance heater electrically insulated
from the recording head material.
The amount of heat energy applied to the dyes, and hence, the
temperature to which the heater is raised will depend upon the
particular sublimable dyes which are used, as well as the desired
vapor pressures. Temperature is an important factor, since if the
temperature is too high the dye will degrade. On the other hand, if
the temperature is too low, the density of recording of the medium
declines. While a combination of variables affects print quality,
it was determined that chamber temperatures of from about 400
degrees F to about 500 degrees F produced the desired print.
As is indicated by the dots in the figure, the dyes will sublime
and form a vaporous state in the upper portion of the respective
chambers 12-15. Means are provided for furnishing a carrier gas to
the upper portion of such chambers for mixture with the dyes. A
reservoir 23 is schematically illustrated for this purpose,
containing a pressurized gas, such as air. Such reservoir is
individually communicated with each of the chambers 12-15, as is
represented in FIG. 2. The result is that a gas under pressure (in
this case air) is mixed with the sublimable dyes in the individual
chambers. The carrier gas is heated to a temperature which will
maintain the dye with which it is mixed in a vaporous state. Most
simply, the dye itself is provided with sufficient thermal energy
to heat the carrier gas with which it is mixed before being ejected
as described below. The structure communicating the reservoir with
the chambers is, in essence, means connecting the sources of
coloring agents with the source of carrier gas.
The recording head 11 includes a nozzle structure 24 on its front
face, having individual nozzles 26-29 communicating respectively
with the dye chambers 12-15. Such nozzles face a recording medium
31 (FIG. 3) at a relatively close spacing. The diameter of the
nozzles 26-29 must be large enough to permit flow such that the
speed of the printer is not limited thereby. This must be balanced,
however, against the need to keep the diameter of, for example,
dots printed, to an appropriate size.
It was found that nozzle diameters of from 20 to 125 micrometers
were useful. Tests were conducted at 20, 75 and 125 micrometers.
Line widths created were as small as 1.5 times the nozzle diameter.
During such tests it was found that spreading of the printed line
beyond the size of the nozzle was due to turning of the stream as
it approached the print surface, and that the jet itself did not
spread significantly over the distances involved. That is, it was
found that distance from the print surface was not critical. In
addition, it was also found that the halo, i.e., background
coloring over a larger area in the vicinity of the nozzle, can be
eliminated by applying an air flow across the printing surface at
the jet. The cross-jet-flow air flow eliminates the halo, thus
providing a sharper print.
As is conventional, the recording medium can be, for example, a
sheet of paper or plastic upon which it is desired to impart
graphical representations.
Because the coloring agent-carrier gas mixture is under pressure,
it is important that the individual nozzles 26-29 be gated. In the
dye chambers pressures of from about 0.1 p.s.i. to about 2.0 p.s.i.
are advantageously used. If the chamber pressure is too high, dye
will be ejected from the nozzle at excessive speed, causing the dye
to spread before adhering to the recording medium. If the chamber
pressure is too low, the ejected dye may cool before reaching the
medium and will therefore not properly adhere.
FIG. 5 illustrates an embodiment of a gate or shutter arrangement
which can be used to provide gating. With reference to such figure,
a gate 32 is shown in the outlet port of the illustrated nozzle.
Such gate includes not only an annulus 33 restricting the size of
the nozzle orifice, but an electrostriction vibrator 34 for
controlling opening and closing of the nozzle orifice. It should be
noted that the carrier gas sublimable dye mixture will be at a
relatively high temperature of between 400 and 500 degrees F. Thus
it is important that the vibrator 34 be one which is capable of
withstanding and operating under such high temperature
conditions.
A voltage is applied to the electrostriction vibrator to open and
close the same, the application of which voltage is controlled by
an image signal source. Such source is schematically represented in
the figures by block 36. Each of the nozzles includes a gate for
controlling the flow of the mixture in its associated dye chamber
therefrom. This is schematically represented in FIG. 4 by the
illustration of flow lines extending from the source 36 to each of
the nozzles.
FIG. 6 illustrates another type of nozzle gating device that may be
used with the instant invention. It is similar to the gating device
shown in FIG. 5 and like reference numerals are used for common
parts. Such device, generally referred to by the reference numeral
37, includes an electromagnet 38 for vibrating a gate valve 39.
Again, because the carrier gas sublimable dye mixture is at a
relatively high temperature, it is desirable that the Curie
temperature of the core portion of the electromagnet be above 300
degrees C.
It is believed that the method of the invention is readily apparent
from the above description of the apparatus of the first
embodiment. The coloring agents in the individual chambers (in this
case, sublimable dyes in their vaporous state) are mixed with a
carrier gas and thereafter the mixture is ejected toward the
desired location on the recording medium The configuration of each
of the chambers assures that there is an intimate mixture of the
coloring agent and gas to form a generally uniform mixture prior to
it being ejected. Moreover, the carrier gas is provided under
pressure. This results in the mixture also being pressurized. The
carrier gas is indirectly heated to assure that it will maintain
the coloring agent in vaporous form between the time the individual
mixtures are jetted from the nozzles and they strike the recording
medium. In this particular arrangement in which the coloring agent
is a sublimable dye, sufficient thermal energy is provided to each
solid dye both to form and maintain its vaporous state and also to
heat the carrier gas with which each is mixed. The carrier gas
should be heated to a temperature at or above the temperature at
which the sublimable dye will maintain its vaporous phase during
travel to the recording medium. Ejection of the mixture toward the
recording medium is controlled to occur only when it is desired, by
the gating devices.
FIGS. 7 and 8 are timing charts which indicate how with vibration
of the gates of one of the respective nozzle gating devices, the
amount of mixture ejected from a nozzle can be controlled. Periodic
time demarcations or intervals are represented in such figures by
uniformly separated lines, the distance between any two of which is
the same, as is represented by TD. The vibration rate provided by a
gating device of a nozzle is represented in the figures by pulses
39. Each of these pulses represents an "open" state of a gate and
the frequency and amplitude of all of such pulses are the same,
with the result that each represents a predetermined amount of
carrier gas-coloring agent mixture which is allowed to eject. (This
is assuming, of course, that the pressure within each of the dye
chambers remains relatively constant.) It thus will be seen that
during any selected time interval TD, the number of pulses which
are applied to a gating device will control the amount of mixture
which actually is ejected during such time interval.
Various colors can be obtained on the recording medium by mixing
the vaporous dyes. To this end, the directions of the nozzles may
be set so that the carrier gas coloring agent mixture of a plural
number of them will be converged to the same spot on the recording
medium. Alternatively, the vaporous dye can be made to impinge at
different locations on the recording medium. It will be appreciated
that sequential passing of a recording head by the same spots on
the recording medium can be used to mix different colors at a
single spot to form a desired color.
The following parameters are suggested as guidelines for the design
of specific equipment utilizing air as a carrier gas and sublimable
dyes:
Temperature: 400 degrees F (204 degrees C)
Orifice: 20-micrometer diameter
Carrier gas pressure: 0.1 psi (700 Pa)
Printing speed: 1 cm/s
Full-width array: 250 lines (nozzles)/inch
Gating frequency: 2000 Hz
In some situations, depending largely on the sublimable dyes which
are selected, it is desirable to be able to control the thermal
energy imparted to each separately, in spite of the fact that a
plurality of chambers are provided. FIG. 9 illustrates a simple
modification which can be made to the embodiment which is described
above, to facilitate such separate heat control. The individual dye
chambers 12A-15A are separated from one another by thermally
insulating walls 41-43. The single heater 22 of the earlier
embodiment is replaced by individual heaters 46-49 associated with
the individual chambers and controllable separately. It thus will
be seen that different amounts of thermal energy can be transmitted
to the separate chambers.
Sublimation of the dyes can be enhanced by including high thermal
conductivity material in the chambers with the solid form of the
same. As previously mentioned the sublimable dye is preferably
provided in powder form, and FIG. 10 illustrates metal (steel) shot
51 combined with the same. It is important that the high thermal
conductivity material mixed with the solid sublimable dye be stable
or inert with respect to such dye at the temperatures and pressures
of operation.
The embodiment illustrated in FIG. 10 also includes a schematic
illustration of a power source 52 and an adjusting mechanism 53 for
controlling the pressure of gas to be injected into the illustrated
dye chamber. It will be appreciated that adjustment of such
pressure will change the mixture pressure and, thus, the color
density or proportion obtainable in the ultimate image. Such figure
also illustrates a power source 54 and an adjustment mechanism 56
for the heater 22. This representation is included to bring out the
fact that the mixture pressure and hence the density of the image
also can be adjusted by changing the amount of thermal energy
applied to the sublimable dye. A change in the thermal energy
changes the pressure of the dye in the vaporous state, the ultimate
mixture pressure, and hence, the density of the image.
It is desirable to be able to replenish or change the coloring
agent associated with each nozzle in a rapid manner. The embodiment
of the invention illustrated in FIG. 11 facilitates such an
arrangement. The sublimable dye is provided within a stand-alone
cartridge 61 which is removably securable to the remainder of the
apparatus. That is, the remainder of the apparatus includes a
leafspring 62 which resiliently urges the cartridge 61 into a
pocket of the apparatus sized to fit the same. Such apparatus
includes means for ejecting a carrier gas-vaporous coloring agent
toward a recording medium. In this connection, the apparatus is
provided with a tubular needle 64 that communicates with its nozzle
and is designed to register with and penetrate through an
appropriate seal in the cartridge to provide a passage to the
nozzle for the gas mixture.
The cartridge itself includes a tubular connection 66 extending
from a gas inlet through the volume of the cartridge that may
contain the sublimable dye in solid form to that portion of the
cartridge designed for the vaporous phase of the dye. The apparatus
is provided with a second tube 67 which is designed to penetrate an
appropriate seal into the cartridge for communication with the
tubular connection 66. Means are thus provided for conveying gas
under pressure from a source 68 in the remainder of the apparatus
to the sublimable dye in the cartridge when the dye is in its
vaporous state.
It will be seen that a plurality of stand alone cartridges can be
provided designed to cooperate with the remainder of the apparatus
to apply desired dye to a recording medium 31. Such cartridges can
have differing coloring agents. In this connection it will be
appreciated that because the gas mixture is under pressure and the
passage through the apparatus to the output end of the nozzle is
relatively short, there will be very little mixture of color when
cartridges having differing coloring agents are used sequentially.
The apparatus can include the nozzle, the cartridge, and means (the
heater, gas source nozzle, passage way etc.) for conditioning the
coloring agent for impingement at a desired location on the
recording medium. This embodiment otherwise is similar to the
earlier described embodiments and like reference numerals are used
to refer to common parts.
While the invention has been described in connection with preferred
embodiments, it will be appreciated by those skilled in the art
that various changes can be made. For example, although the
coloring agent is described in the preferred embodiment as being a
sublimable dye, it will be recognized that other types of coloring
agents may also be used appropriately with the invention. Such
coloring agent may itself not provide a desired color. It may be an
acid or other material which will react with the recording medium
to provide a selected color. In view of the various modifications
that can be made, it is intended that the scope of the invention
only be defined by the claims and their equivalents.
* * * * *